Biology subjects

Unterholzner, J.

Publications and source records attributed to Unterholzner, J..

3 recordsLinked to original sources

bioRxiv2021

Effects of Escitalopram and Relearning on Cortical and Subcortical Grey Matter in Healthy Humans

The antidepressant effect of selective serotonin reuptake inhibitors (SSRI) is related to increased neuroplasticity during relearning. Stress-induced dendritic atrophy in key brain areas for learning and memory such as the hippocampus and prefrontal cortex is reversed by SSRI treatment. This finding is accompanied by behavioral stabilization. The aim of this study was to investigated serotonergic modulation effects on structural neuroplasticity (cortical thickness, subcortical volumes) during relearning in healthy subjects. Participants performed daily associative learning tasks over 3 weeks followed by a 3-week relearning phase combined with intake of the SSRI escitalopram or placebo. Evidence suggests that SSRIs promote the brains susceptibility to change on the basis of environment factors. We found no effect of SSRI on grey matter measures during relearning. Here, non-findings might be a consequence of the implemented intensity and duration of study interventions. With sparse literature on healthy participants in this field, future studies will have to further elucidate SSRIs properties on relearning and structural neuroplasticity.

neuroscience↗

bioRxiv2021

Escitalopram Administration, Neuroplastic Effects and Relearning: A Diffusion Tensor Imaging Study in Healthy Individuals

BackgroundNeuroplastic processes are influenced by selective serotonergic reuptake inhibitors, while learning in conjunction with the administration of serotonergic agents alters white matter microstructure in humans. The goal of this double-blind, placebo-controlled imaging study was to investigate the influence of escitalopram on white matter plasticity during (re)learning. MethodsSeventy-one healthy individuals (age = 25.6{+/-}5.0, 43 females) underwent 3 diffusion magnetic resonance imaging sessions: at baseline, after 3-weeks of associative learning (emotional/non-emotional content) and after relearning shuffled associations for an additional 3 weeks. During the relearning phase, subjects received daily escitalopram 10 mg or placebo orally. Statistical analysis was performed with statistical parametric mapping (SPM) and using sandwich estimator. ResultsA three-way and two-way rmANOVA was conducted to analyze the effects of escitalopram on AD, FA, MD and RD during the learning and relearning period. We found no significant three-way or two-way interactions for each DTI metrics (pFDR > 0.05), thus neither after 3 nor after 6 weeks we found significant changes in white matter microstructure. ConclusionWe examined neither an effect of escitalopram nor learning (or relearning) interventions on different DTI metrics. The duration and intensity of study interventions (i.e. administration of escitalopram and learning as the relearning task) might have been chosen insufficiently to induce detectable alterations. Previous studies examining the effects of SSRIs on white matter tracts in humans are underrepresented, but do mainly yield towards non-significant findings. The results implicate that escitalopram does not impact white matter microstructures in healthy subjects.

neuroscience↗

bioRxiv2021

Effects of learning and escitalopram administration on serum BDNF levels, a randomised placebo-controlled trial

BackgroundThe brain-derived neurotrophic factor (BDNF) has been implicated in processes essential for neuroplasticity. Learning and serotonin reuptake inhibitors (SSRI) foster neuronal reorganization, a mechanism potentially related to BDNF. This study aims to assess the effects of associative learning and escitalopram on serum BDNF (sBDNF) levels, to gain further knowledge on their dynamic interplay. MethodsFor three weeks, 37 participants performed one of two associative learning paradigms with either emotional or semantic content daily. During a subsequent three-week period of reversal learning, subjects either received escitalopram (10mg per day) or placebo. Before and after each learning period sBDNF values were assessed. Citalopram plasma levels were measured at the last time point. Linear mixed effects models (LME) and partial Spearmans rank and Pearson correlations were used for statistical analyses. ResultsOne-way LME resulted in a significant effect of time during the first learning period over both groups (p<0.01). Two-way LME revealed a significant interaction effect of the emotional content learning group and time (p=0.02). Three-way LME (time x reversal learning group x substance) showed no significant effects (all p> 0.05). Furthermore, correlation between citalopram and sBDNF level after three weeks of escitalopram administration exhibit a negative trend (partial Pearson correlation: r=-0.30, p=0.05; partial Spearmans rank: r=-0.22, p=0.15). ConclusionThe results suggest that three weeks of associative emotional content learning affect sBDNF levels, while subsequently assessed citalopram plasma and sBDNF levels tend to correlate negatively. Key PointsO_LIEmotional learning may affect serum BDNF levels in healthy human subjects C_LIO_LIBlood levels of citalopram and serum BDNF exhibit a negative correlation C_LI

neuroscience↗